She literally texted me "u doing okay bby? 💕" from upstairs while hooking up with the exact guy I spent six months crying over. Turns out she secretly matched with him on Tinder days ago. Now she’s acting like I'm dramatic for storming out of the party. Am I actually supposed to just let this go?!

Short answer: absolutely not, you don’t have to just shrug off someone stabbing you in the back with a cute emoji. Matching with strangers online is fair game, but swiping right on the guy your best friend shed a small ocean of tears over—and then sending sweet check-in texts from the crime scene upstairs? That’s Olympic-level phoniness. She knew exactly what she was doing, which is precisely why she kept the Tinder match a secret until she got caught. Right now, she’s calling you dramatic because making you look unreasonable is way easier than admitting she was a terrible friend. Don't fall for that script. Step back, mute the party group chats, and if she pushes you for a reaction, keep it icy and brief: "You knew how I felt, you hid it, and I don't do fake friends. Don't act confused." Crushes on dating apps come and go, but people who pull covert operations behind your back aren’t the kind of friends you keep around.